1. Field of the Invention
The present invention relates to burrowing vermin pests which dig and occupy underground tunnels. More particularly it relates to a method of fumigation using heated gas and oils, which not only exterminates the current occupants of such tunnels, the method renders the tunnels uninhabitable by other subsequent burrowing rodents and mammals who may attempt occupancy. Such is accomplished by employing generating smoke which imparts a long lasting scent which experimentation has shown such animals will avoid.
2. Prior Art
There are many types of burrowing pests which dig and occupy tunnels and burrows. While decades in the past, such animals often had their populations naturally controlled by predators such as coyotes, foxes, and the like, modernly such underground pests have adapted to live and burrow in areas where few such predators exist.
Living free of substantial risk from predators in fields and back yards, there has been a resulting explosion in the population of burrowing animals, and the problems associated with them. Gophers are well known burrowing pests and are similar to most such animals. The term gopher as it is commonly used does not relate to any one species, but is a generic term used to describe any of several small burrowing rodents endemic to North America, including the pocket gopher (family Geomyidae), also called true gophers, and the ground squirrel, including Richardson's ground squirrel and the species of prairie dog.
Gophers in this group of burrowing animals can vary in size and often weigh around 0.5 pounds (230 g), and are about 15 inches (38 cm) long in body length, with a tail 7 inches (18 cm) long. They are well adapted to living underground in tunnels.
Consequently, gophers and similar burrowing vermin dig tunnels and subterranean chambers, and are associated with the rodent order. With their constant burrowing and eating of decorative and food crops, the over one hundred kinds of gophers in America continually disrupt human endeavors such as commercial agriculture, garden plots, landscaping, and even underground communication cables. The penchant of such burrowing creatures for digging and chewing, and their exploding population caused by lack of predators, has led to their treatment as unwanted pests who cause significant financial and ecological harm.
Gophers and similar burrowing creatures create a large community of tunnels with large mounds of dirt and rocks at their entrances, sometimes referred to as gopher towns. In some species, burrowing rodents will frequently position one or more members of the troop to stand watch at the entrance to a tunnel who will whistle when predators are spotted. This signal causes the other gophers to run for the safety of the tunnels making it hard for predators unused to this behavior to thin the herd. As such gophers and other rodents breed rapidly, in a short span of time a gopher town can easily spread to take over large sections of yards, gardens, and meadows, and may have a population from dozens to hundreds depending on the territory and food supply. The resulting destruction of plant life caused by large and small groups of such vermin leave the area a stretch of denuded dirt.
As a consequence of the exploding populations, many exterminating techniques for burrowing vermin such as gophers have evolved. Many modern techniques involve the application of poisonous chemicals, smoke, or gasses being introduced into the burrow in efforts to kill the inhabitants. U.S. Pat. No. 5,548,921 to Kleisath teaches a method and apparatus for gassing gophers, comprising a device for introducing dry chlorine material and water into a burrow. The combination of dry chlorine and water produces chlorine gas for effective poisoning of the gopher. However, for the average consumer, the use and handling of poisonous materials may not be desirable, especially if they have children. Further, the employment of such chemicals often leaves residual toxins in the soil long after use and which can be toxic to humans.
U.S. Pat. No. 7,249,437 to Stout teaches a method and apparatus for exterminating burrowing pests where a first agent is introduced into the burrow to destabilize the pest, followed by a second agent for killing them. The method taught in Stout effectively administers a lethal dose of poison before the animal can escape or hide within the burrow. Although providing a means to exterminate burrowing pests, the method and apparatus taught by Stout does not seem economically viable for the average consumer.
U.S. Pat. No. 4,829,706 to Perry teaches an apparatus for introducing the poisonous exhaust gasses of a two cycle engine into a burrow. The device includes a bowl shaped exhaust shroud for placing over a burrow entrance and directing the exhaust gasses. However, the smoke produced and level of toxicity of the exhaust gasses is limited to what the internal engine can burn, and lacks any ability to combine the delivered gas with another agent. Neither does the Perry reference provide and residual deterrence to re-occupancy of the deserted tunnels and as such is not suitable for reliable and long term extermination.
As such there is a continuing and unmet need for an improved device for directing communicating gasses under pressure into the long tunnels of a burrow. In order to provide a long term deterrent to immediate re-occupation by other rodents, such a communicable gas should render the tunnels uninhabitable. Such a long term deterrence to habitation by other rodents should be in a form which is harmless to humans, but avoided by gophers and other rodents for a term to allow the tunnels to collapse.
Still further, in order to eliminate the need to purchase specialized equipment, such a method should be employable with multiple means for delivering a pressurized gas stream to tunnels and in on mode should be employable with a device which is easily engageable to a conventional internal combustion engine through a communication with the exhaust pipe, stand-alone small engine or employing in combination with a car, or motorcycle, or other wheeled vehicle having an internal combustion engine. Such a method should be easily employable with a device for heating the fluid providing the extermination and long term deterrence, using a portable and easily positionable for communication of heated gas to burrow entry points.